Communications on Pure and Applied Mathematics · 1969 · 80 citations · 4 references
Natural SciencesMathematicsDynamical SystemsEigenvalue ProblemsOperator TheoryPerturbation MethodsPerturbation TheorySingular Perturbation TheorySpectral TheoryMatrix Perturbation TheoryPerturbation Theory Of OperatorsSelf-adjoint OperatorsSingular Perturbation AnalysisSingular Perturbations In Partial Differential Equations
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